Method And Device For Representing A Digital Image On A Surface Which Is Non-Trivial In Terms Of Its Geometry And Photometry

Abstract

The invention relates to a method and a device for representing a two-dimensional digital image on a projection surface, whereby at least one projector projects the content of an image buffer onto the projection surface. The aim of the invention is to provide a method and a device which allow to project a digital image onto a background having any surface structure and / or color in such a manner that any influences on the image caused by the background are compensated to the last pixel for at least one special observer perspective. In a special embodiment, definition of the representation is optimized to the last pixel even on an uneven background. For this purpose, the digital image is processed during a rendering step by geometrically distorting it using a two-dimensional pixel-offset field which contains information on the projection surface, and by manipulating the color of the image by means of a two-dimensional surface texture of the projection surface. A least a part of the processed image is rendered in an image buffer and a rectangle is written into the image buffer for initiating the rendering step, thereby compensating scattered light influences. The invention especially relates to a system comprising a plurality of projectors. Definition of representation can be optimized to the last pixel by means of definition values and representation is furthermore possible subject to the observer's position.

Description

BACKGROUND OF THE INVENTION [0001] The invention relates to a method and an apparatus for representing a digital image on a projection surface, and the content of an image buffer being projected onto the projection surface by means of a projector. [0002] In the context of the invention, a projection surface is in principle any desired surface. In particular a projection surface in the context of the invention can be a surface that is non-trivial in terms of geometry and photometry that, for instance, has any desired three-dimensional shape and / or any desired texture. In the context of the invention a projection surface can in particular also comprise a plurality of partial surfaces. [0003] A system is known from DE 102 51 217 B3 for automatic calibration of multiple projector systems that has at least two projectors, one digital camera, and a control unit for controlling the projectors and the camera, automatic calibration occurring with the steps of generation, recording and image ...

AI Technical Summary

Benefits of technology

"The invention provides a method for accurately projecting a digital image onto a non-planar surface, such as a wall or a car, using a single or multiple projectors. The method includes processing the image using a pixel displacement map that takes into account the geometry and color of the surface. The method can be performed in real-time and with modern computer hardware. The calibration is done by projecting a calibration image onto the surface and recording the image using a camera. The recorded image is then used as a texture map for the surface. The method can be repeated with different camera positions to optimize the representation for different observers. The invention allows for accurate and reliable calibration and representation of complex surfaces with non-planar geometry and texture."

Problems solved by technology

Pixel-exact warping is not possible with this system.

It is furthermore disadvantageous that non-white texturizing or differences in texturizing of the projection surface have a negative effect on the display.

Recordings of natural scenes, especially in the dark, frequently do not have high contrast and therefore do not have an adequate number of edges.

This has a negative effect on the quality of the passive autofocus mechanisms in the cameras.

Defocused projection causes them to become even less defined, which distorts the depth perception.

However, this solution is extremely costly.

In addition, the laser projectors used have a major disadvantage.

Mobile use of laser projectors is therefore very complex.

These methods are not suitable for representing moving contents with active display devices such as projectors.

Images